Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average sea temperature in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The onset of September notes an average high-temperature of an enjoyable 64.8°F (18.2°C), subtly shifted from August's 70°F (21.1°C). In September, Birch Bay encounters an average low-temperature of 52°F (11.1°C) during the night.Humidity
In September, the average relative humidity is 79%.Rainfall
In Birch Bay, in September, it is raining for 12.8 days, with typically 2.36" (60mm) of accumulated precipitation. Throughout the year, there are 176.1 rainfall days, and 43.78" (1112mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in Birch Bay.Ocean temperature
In Birch Bay, in September, the average water temperature is 52.5°F (11.4°C).Note: Danger awaits those who swim in 52.5°F (11.4°C) without protection. Falling below 50°F (10°C) means intense cold shock and hyperventilation.
Daylight
In Birch Bay, the average length of the day in September is 12h and 34min.On the first day of September, sunrise is at 6:28 am and sunset at 7:52 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:50 pm PDT.
Sunshine
The average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the average person.Note: The maximum UV index, 3 during September, leads to the following recommendations:
Take necessary precautions - Defending against sun damage is advocated. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the ocean temperature in September?
How many hours of daylight does Birch Bay have in September?
When are sunrise and sunset in September in Birch Bay?
How many hours of sunshine does Birch Bay have in September?
What is the UV index intensity in September?
Average temperature in September
Birch Bay, WA
- Average high temperature in September: 64.8°F
The warmest month (with the highest average high temperature) is August (70°F).
The month with the lowest average high temperature is December (41.9°F).
- Average low temperature in September: 52°F
The month with the highest average low temperature is August (54.9°F).
The coldest month (with the lowest average low temperature) is February (35.8°F).
Average pressure in September
Birch Bay, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.07"Hg).
The month with the lowest atmospheric pressure is March (30"Hg).
Average wind speed in September
Birch Bay, WA
- Average wind speed in September: 4.3mph
The windiest months (with the highest average wind speed) are November and December (6.3mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in September
Birch Bay, WA
- Average humidity in September: 79%
The months with the highest relative humidity are January and November (83%).
The month with the lowest relative humidity is July (74%).
Average rainfall in September
Birch Bay, WA
- Average rainfall in September: 2.36"
The wettest month (with the highest rainfall) is November (7.13").
The driest month (with the least rainfall) is July (0.67").
Average rainfall days in September
Birch Bay, WA
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (6.1 days).
Average snowfall in September
Birch Bay, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.05").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Birch Bay, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.7 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
Birch Bay, WA
- Average sea temperature in September: 52.6°F
The best months for swimming (with the highest average sea temperature) are August and September (52.6°F).
The coldest month (with the lowest average sea temperature) is February (44.5°F).
Average daylight in September /
Average sunshine in September
Birch Bay, WA
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 18min).
- Average sunshine in September: 8h and 5min
The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The months with the least sunshine are January and December (Average sunshine: 3h and 54min).
Average sunshine days in September
Birch Bay, WA
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is August (23.2 days).
The month with the least sunshine days is November (8.8 days).
Average UV index in September
Birch Bay, WA
- Average UV index in September: 3
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Birch Bay, WA
- Average cloud cover in September: 35
The months with the most cloud cover are January and December (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in September
Birch Bay, WA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Birch Bay, Washington, USA
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